Daniel Ferenczi

`mix firmware` fails on Nix due to hardcoded lib paths

2

### Environment * Elixir version (`elixir -v`): ``` Erlang/OTP 25 [erts-13.2.2] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1] Elixir 1.14.4 (compiled with Erlang/OTP 25) ``` * Nerves environment: (`mix nerves.env --info`) ```...